Field of the Invention
The present invention relates to keyless entry systems with dynamic and random positioning of input choices to avoid compromising entry codes by observation.
Background of the Related Art
Automotive keyless entry systems, when first introduced, typically included a numerical keypad located on the exterior door panel of the vehicle. The operator entered an access code, a unique multiple digit code on a static keypad, to automatically unlock or lock the vehicle. One such static keyless entry for an automobile using a key pad is disclosed in U.S. Pat. No. 5,467,080 to Stoll et al., which is incorporated herein by reference. In that system, a control keypad is integrated into the vehicle so that entry of a code on that keypad signals the car to perform a certain function, e.g. opening the door. In that system, however, the positions of the numbers on the keypad are static, i.e., the positions of the keys are always the same. For example, the number 1 is always in the same position; the number 2 is always in the same position; and so forth, as shown in FIG. 1. Further referring to FIG. 1, in a typical alpha numeric keyless entry system 50 the key pad shows the numbers 55 in sequential order. In a static system 50, the pattern that the user enters an access code is always the same. For example, if the entry code value sequence is 5-4-6-2, the entry pattern will always be the same in FIG. 1.
These systems are prone to compromise when another person observes the user pressing the static key positions and values to input the user's protected access code on a static key pad because the numbers are always in the same location, and thus the entry pattern is always the same for a given access code. As a result, the observer can determine the protected access code entry pattern.
Therefore, a need remains for a system whereby the entry pattern of an access code is dynamic (not static and having the same display pattern), so that the same access code entry pattern does not result every time the same access code is entered.